This invention relates generally to an engine having a predetermined set maximum power rating based on less than ideal site and ambient conditions, and more specifically to controlling the engine to produce a quantity of power in excess of the predetermined set maximum power rating as a function of engine operating conditions.
Many engines are coupled with generators to produce electrical power. These engines are typically configured during manufacture to produce up to a predetermined set power rating. More specifically, an engine controller is normally configured to command the engine to produce up to and no more than the predetermined maximum power rating.
The predetermined maximum power rating of a particular engine is often calculated using worst case operating conditions for the engine. This is because the amount of power that the engine is capable of producing is usually limited by its operating conditions. For example, if the ambient temperature is very warm, e.g., 43 degrees Celsius, the temperature of the air or air/fuel mixture being sent to the combustion chamber cannot be as cool as a day when a substantially cooler ambient air temperature exists. Within a fairly wide range, the temperature of the air or air/fuel mixture being sent to the combustion chamber has a direct impact on engine power capability.
The example in the paragraph above generally covers an operating condition where cooler water to the aftercooler (aftercooler water temperature) results in a power increase because the inlet manifold temperature is reduced. Similarly, other engine operating conditions, such as jacket water temperature, inlet manifold pressure, humidity, and whether detonation is occurring during ignition may all affect combustion, and therefore power production.
Further, many engine controllers limit the power production of an engine to a predetermined set maximum power rating. Thus, even when an engine is operating in better than worst case operating conditions, the engine controller may still use predetermined worst case conditions for calculating the power output. In this instance, the engine typically produces less power than it could, with the additional power producing capabilities of the engine remaining unused.
The present invention provides methods and apparatus for controlling an engine having a first maximum power rating based on at least a first predetermined operating condition of the engine. A first sensor transmits a first signal as a function of the engine operating at a predetermined operating condition other than the first predetermined operating condition. A control device receives the first signal and transmits a power signal to the engine as a function of the first signal. The power signal causes the engine to produce a quantity of power in excess of the first maximum power rating.